宁波市地中海贫血筛查及基因分型

Screening and genotyping of thalassemia in Ningbo

目的了解宁波市人群地中海贫血(简称地贫)基因分型情况,为今后宁波市地贫防控提供参考依据。方法选取2019年1月至2022年3月在宁波市妇女儿童医院就诊的疑似地贫患者为研究对象,采集末梢血制成干血斑标本并提取DNA。采用荧光PCR熔解曲线分析技术结合Sanger测序或多重连接依赖探针扩增(MLPA)进行地贫热点变异基因检测。结果共纳入疑似地贫患者2680例,检出地贫基因携带者1426例,总检出率为53.2%。其中,α-地贫595例,占41.7%,以--SEA/αα、αα/-α3.7和--SEA/-α3.7较常见;β-地贫807例,占56.6%,以βIVS-Ⅱ-654/βN、βCD41-42/βN、βCD17/βN较常见;αβ-复合型地贫24例,占1.7%。其中,包括6种罕见变异类型,包括融合基因(Fusion)、--FIL、HBA2:c.376C>T、CD8/9(+G)、IVS-Ⅰ-2(T>C)和IVS-Ⅱ-1(G>A),均为宁波市的首次报道。结论宁波市疑似地贫患者中,地贫检出率较高,基因变异类型复杂,应提高对贫血患者行地贫基因检测的意识。

Objective To study the genotyping of thalassemia in Ningbo population and provide a reference basis for future prevention and control of thalassemia in Ningbo.Methods Patients with suspected thalassemia attending Ningbo Women and Children's Hospital from January 2019 to March 2022 were selected for the study,and DNA was extracted from dried blood spot specimens by collecting peripheral blood,and detection of thalassemia hotspot variants was performed by fluorescence PCR melting curve analysis combined with Sanger sequencing or multiplex ligation-dependent probe amplification(MLPA).Results A total of 2680 cases were included in the patients with suspected thalassemia,and 1426 cases of thalassemia gene carriers were detected,with an overall detection rate of 53.2%.Among them,595 cases(41.7%)wereα-thalassemia,with--SEA/αα,αα/-α3.7 and--SEA/-α3.7 being more common;807 cases(56.6%)wereβ-thalassemia,withβIVS-Ⅱ-654/βN,βCD41-42/βN andβCD17/βN being more common;24 cases(1.7%)wereαβ-combined thalassemia.Among them,six rare variant types were included,including fusion gene(Fusion),--FIL,HBA2:c.376C>T,CD8/9(+G),IVS-Ⅰ-2(T>C)and IVS-Ⅱ-1(G>A),all of which were reported for the first time in Ningbo.Conclusion Among suspected thalassemia patients in Ningbo,the detection rate of thalassemia is high,and the types of gene variants are complex,so the awareness of thalassemia gene testing for anemic patients should be raised.